Hi,
I don't think that the negative space is too much here, I would even argue that it lacks negative space (water and sky).
But What I am wondering more about is the horizon... it's smack in the middle, and that makes the composition a bit boring, it's lacking tension, and I feel like that there is too much going on, maybe it's the ducks in the foreground. I also have a feeling that it is slightly out of focus, either you overshot infinity by a hair, or it's motion blur/camera shake, can't tell.
otherwise, I think the processing is not bad.
good luck